Potassium ion channel proteins regulate electrical signaling in nervous systems. W'hile the crystal structure of a typical K' channel such as Streptomyces fividans membrane protein KcSA has been solved, the gating mechanism and the location topology in the membrane bilayer are not yet fully understood. High resolution solid-state NMR offers a number of ways to study the process in the solid state. We suggest to use "Ti as a probe for analyzing location and movements of ions inside the protein. "TI NMR in solid state offers a number of advantages; high gyromagnetic ratio of "'TI and its large chemical shift dispersion allow to observe local structure with high sensitivity and efficiency. Preliminary experiments on model systems have been successfully performed. Our goal is to conduct variable temperature experiments on KcSA ion channel in order to determine the number of ion-binding sites, their topology and the dynamics of the process.